2-[2-(2-{2-[2-(2-Benzyl-3-phenyl-propionylamino)-3-methyl-butyrylamino]-3-methyl-butyrylamino}-4-oxo-4-pyrrolidin-1-yl-butyrylamino)-3-carboxy-propionylamino]-4-methyl-pentanoic acid AIDS-188203 AIDS188203